Background: The main goal of behavioural finance is to investigate the impacts of behavioural factors on financial factors. One of the issues that can affect investors' decisions is their personality traits. Commitment to ethics is the one of the effective issues that emerges in behavior. The aim of this study was to investigate the relationship between professional ethics and personality traits of investors.Method: This is an applied research by descriptive-correlation method. Population of study includes all investors. Among all, 153 subjects were participated in this study. Data were gathered by questionnaire and were analyzed by Pearson correlation test.Results: The findings show that there is significant and positive correlation between professional ethics and extroversion, compliance, conscientiousness and openness to experience, while there is significant and negative correlation between professional ethics and neuroticism.Conclusion: According to the findings, it could be concluded that there is significant correlation between personality traits and professionals ethics, indicating the importance of professional ethics and the need to pay more attention to such an issue.